Back-spacing attachment fo type-writing machines.



No. 765,367. PATENTED JULY 19, 1904. W. A. PARKER.

BACK SPAGING ATTAGHMBNT FOR TYPE WRITING MACHINES.

APPLICATION FILED we. 25, 1903.

r0 MODEL.

W1TNESSES: [NVENTOR WM. By

Patented July 19, 1904.

PATENT OFFICE.

WILLIAM A. PARKER, OF VVAOO, TEXAS.

BACK-SPACING ATTACHMENT FOR TYPE-WRITING MACHINES.

SPECIFICATION forming part of Letters Patent No. 765,367, dated July 19,1904.

Application fil d August 25, 1903.. Serial No. 170,724. (No model.)

To all whom, it may concern:

Be it known that I, WILLIAM A. PARKER, a citizen of the United States,residing at Waco, in the county of McLennan and State of Texas, haveinvented certain new and useful Improvements in Back-Spacing Attachmentsfor Type-VVriting Machines, of which the following is a specification.

This invention relates to a back-spacing attachment for type-writingmachines, and particularly to one having special utility on an Olivertype-writer.

To this end the invention has in view the provision of a simple,practical, and conveniently-operated spacing attachment designed toobviate the necessity of removing the hands from the keyboard when it isdesired to back the carriage one or more spaces for corrections orinsertions. plished by handling the carriage, which is inconvenient andentails a loss of time. The presentinvention permits this operation tobe effected quickly and accurately.

Furthermore, the invention contemplates an attachment requiring nochange whatever in the machine and which does not interfere in the leastwith the usual operation thereof.-

detail in perspective of the complete attachment removed from themachine. Fig. L is aperspective View of the complete attachment, showingthe several elements thereof separated.

Like reference-numerals designate corresponding parts in the severalfigures of the drawings.

In carrying out the present invention the attachment as an entirety isfitted directly to Usually this is accomthe type-writing machine withoutchanging any part of the latter. As the attachment possesses specialutility in connection with an Oliver type-writing machine, this type ofmachine is illustrated in the drawings, and the same embodies in itsgeneral organization a traveling carriage l, which carries theescapement-rack 2, with which cooperates the spacing-pinion 3,controlled through the medium of the ordinary spacing mechanism, andwhich permits the carriage to be freely moved backward or to the right,as is common to most forms of type-writing machines. It is the purposeof the present invention to accom plish this backward movement of thecarriage a space at a time through the medium of a finger-controlledattachment.

This attachment essentially comprises a supporting member 4, afinger-operated spacelever 5, and a pivotal spacing-clog 6. Thesupporting member is preferably in the form of an angled bracket whichincludes an attaching-plate 7, which is conveniently screwed orotherwise suitably fastened upon one side of the upright frame member 8,which in the Oliver type-writing machine is what is commonly known asthe ribbon-throw upright and which is located within the central portionof the machine in rear of the keyboard, but in proximity thereto. Theupper horizontal portion 8 of the supporting member or bracket 4 haspivotally mounted thereon the space-lever 5. The pivotal support 9 forsaid lever is arranged at an intermediate point between the endsthereof, and the lever-arm extending forwardly from the pivot 9 towardthe keyboard is provided at its front terminal with a finger plate orbutton 10, which practically constitutes a part of the keyboard and maybe easily reached by the operator extending the index-finger forwardover the back row of keys.

The space-lever 5 is of an angled form, and upon the rear end portionthereof is pivotally mounted, through the medium of the pivot 11, thepivotal spacing-dog 6. The. spacingdog 6 lies in operative proximity tothe escapement-rack 2 and is formed at one corner with arearwardly-deflected thrust-tooth 12, adapted to be moved intoengagement with the teeth of the rack and at the same time thrust in adirection for forcing the carriage backward. In addition to thethrust-tooth 12 the pivotal spacing-dog 6 is also provided at a pointnearer its pivot with a short rearwardly-projecting check-tooth 13,which is adapted to come into engagement with the rack-teeth just beforethe carriage has finished its backward movement of one space to theright, thereby stopping the further movement of the space-lever andpreventing the carriage from moving more than one space to the right ata time.

In further explanation of the short checktooth 13 it will be noted thatthe same is of less projection from the body of the dog than thethrust-tooth l2, and therefore comes into engagement with the rack-teetha little later than the engagement of the thrusttooth. Without thecheck-tooth 13 there would be under extra pressure on the space-lever atendency for the point of the thrust'tooth 12 to press farther into andagainst the rack-teeth, with the result of moving the carriage more thanone space; but this tendency is checked by the check-tooth 13 cominginto engagement with the rack-teeth just before the carriage hasfinished its movement of one space.

At its back edge the dog 6 is provided with an angled seat forming aholding-shoulder 14, adapted to fit against the upright frame member 8,so as to hold the dog in an inactive position when the space-lever isheld in or drawn back to its normal position under the influence of theretracting-spring 15, connected, respectively, with the lever 5 and itssupport 4.

An adjusting-spring 16 of less strength than the spring 15 is connected,respectively, with the toothed portion of the dog and the lever 5, sothat when the space-lever 5 is moved in a direction to carry the dogaway from the frame member 8 the dog will be tilted upon its pivot oraxis in a direction for carrying the thrust-tooth 12 into engagementwith the teeth of the rack. The movement of the dog in this directionunder the influence of the spring 16 is checked by the stop arm 16thereof engaging with a stop projection 17 upon the space-lever.

When the finger-pressure is released from the space-lever, the spring 15returns it to normal position, and the superior strength of said springovercomes the said adjustingspring by drawing the dog against theupright 7 and causing it to tilt back to its inactive position.

From the foregoing it is thought that the invention and its action willbe readily understood. It will also be understood that changes its rearend a self-adjusting spacing-dog normally restrained in an inactiveposition by engagement with said fixed member.

2. In a spacing attachment of the class described. the combination withthe machine element bearing the escapement-rack, of apivotally-supported space-lever arranged contiguous to the keyboard andcarrying directly upon one end thereof aspaeing-dog provided withseparate thrust and cheek teeth arranged one in advance of the other,and one being of less projection than the other from the body of thedog.

3. In a back-spacing attachment for typewriters, the combination withthe escapementrack, a frame-upright directly adjacent to said rack, anda keyboard in front of the rack, of a single horizontal swingingspace-lever arranged in the interval between the keyboard and rack andmounted upon the frame-upright, said space-lever having at its front enda finger-engaging portion and carrying directly upon its rear end aspacing-dog cooperating with the rack.

4C. In a spacing attachment of the class described, the combination withthe machine element bearing the escapement-rack, and a frame-upright, ofa spring-retracted and finger-actuated space-lever pivotally sustainedupon said upright, and a spring-adjusted spacing-dog pivotally mountedupon one end portion of the space-lever and provided at one end with athrust-tooth for engaging with the rack and also with a shortcheck-tooth arranged in a different plane from the point of thethrust-tooth, said spacing-dog being further provided at its back edgewith an angled holding shoulder or seat engaging with the frame-upright.

In testimony whereof I aflix my signature in presence of two witnesses.

WILLIAM A. PARKER.

Witnesses:

W. H. KENDALL, NORMAN H. SMITH.

